FIG. 9.

Proteasome inhibitors prevent establishment of an IFN-α response against HCV replicons. (A) GS4.1 cells were treated with IFN-α for 10 h, followed by treatment with the indicated proteasome inhibitors for 12 h. Cells were left untreated (lanes 1 to 3 and 4 to 6) or treated with 100 IU of IFN-α/ml for 10 h (lanes 7 to 18), followed by treatment with 10 μM lactacystin (lanes 13 to 15) or 1 μM epoxomicin (lanes 16 to 18) for 12 h. Cells were harvested at 0, 10, and 18 h after the cytokine treatment, as indicated. Viral RNA levels were determined by Northern blot analysis. rRNA was used as a control for the amount of RNA present in the samples. (B) The amount of viral RNA was measured with a phosphorimager and the mean values and standard deviations from three samples were plotted. PSL, arbitrary units.